With increasing development of image processing technologies, flatbed image scanners become essential electronic devices for scanning documents. The images of the scanned documents are converted into image files, which can be stored in a computer or further processed by the computer.
Referring to FIG. 1(a), a schematic view of a flatbed image scanner is illustrated. As shown in FIG. 1(a), the flatbed image scanner 1 comprises a glass platform 11 and an optical scanning module 13. The glass platform 11 is used for placing thereon a document 12 to be scanned. The optical scanning module 13 is the main component of the flatbed image scanner 1. After the document 12 is placed on the glass platform 11, the optical scanning module 13 is moved along the scanning direction so as to scan the document 12.
Please refer to FIG. 1(b), which is a cross-sectional side view illustrating the internal components of the optical scanning module 13. In the housing 130 of the optical scanning module 13, a light source 131, a reflective mirror set 132, an optical lens 133 and an optical sensor 134 are included. A light-transmissible window 135 is arranged in the top surface of the housing 130. The process for performing a scanning operation will be illustrated as follows. Firstly, the light emitted by the light source 131 is projected onto the document 12 to be scanned. The light reflected from the opaque object 14 is then transmitted into the optical scanning module 13 through the light-transmissible window 135, which is arranged in the top surface of the housing 130. After passing through the light-transmissible window 135, the light is successively reflected by the plural reflective mirrors of the reflective mirror set 132, and then focused by the optical lens 133. The focused light is then imaged onto the optical sensor 134 to convert the optical signals reflected from the scanned document 12 into corresponding image signals.
As known, heat is generated during the optical scanning module 12 performs the scanning operation on the document 12. On the other hand, in a case a flatbed image scanner having relatively large volume and ordinary resolution, the electronic components included in the optical scanning module 13, for example the optical sensor, are not evidently and adversely influenced by the heat generation.
Since the image scanner is developed toward increased resolution and slim volume, the heat generated from the optical scanning module 13 may impair the scanning quality of the flatbed image scanner. Therefore, it is desired to remove the heat generated from the optical scanning module 13.
A heat-dissipating mechanism for use with a light source assembly of an optical scanner described in Taiwanese Patent Gazette No. 461657, and the contents of which are hereby incorporated by reference. A schematic cross-sectional view of the light source assembly as disclosed in Taiwanese Patent No. 461657 is illustrated in FIG. 2. As shown in FIG. 2, the light source assembly 2 comprises a lamp tube 20, a lamp holder 21 and a rubber body 22. The lamp tube 20 is sheathed by the rubber body 22 and fixed on the lamp holder 21 via the rubber body 22. In accordance with the main feature of this reference, a plurality of heat sink fins 23 are integrally formed on the surface of the lamp tube 20. During scanning operation, the heat generated from the lamp tube 20 is conducted to the heat sink fins 23 and then radiated from the heat sink fins 23 to the ambient air so as to achieve the object of heat dissipation. For increasing the heat-dissipating efficiency, an addition fan assembly (not shown) is provided. Since the heat sink fins 23 and the fan occupy much space inside the optical scanning module, the flatbed image scanner fails to be made in a slim type.
In views of the above-described disadvantages of the prior art, the applicant keeps on carving unflaggingly to develop an improved optical scanner according to the present invention through wholehearted experience and research.